modules/codec/stl.c

   1 /*****************************************************************************
   2  * stl.c: EBU STL decoder
   3  *****************************************************************************
   4  * Copyright (C) 2010 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30 #include <assert.h>
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_codec.h>
  35 #include <vlc_memory.h>
  36
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  Open (vlc_object_t *);
  41 static void Close(vlc_object_t *);
  42
  43 vlc_module_begin()
  44     set_description(N_("EBU STL subtitles decoder"))
  45     set_category(CAT_INPUT)
  46     set_subcategory(SUBCAT_INPUT_SCODEC)
  47     set_capability("decoder", 10)
  48     set_callbacks(Open, Close)
  49 vlc_module_end()
  50
  51 /*****************************************************************************
  52  * Local definitions/prototypes
  53  *****************************************************************************/
  54 struct decoder_sys_t {
  55     int dummy;
  56 };
  57
  58 static char *ParseText(uint8_t *data, int size)
  59 {
  60     char *text = strdup("");
  61     int  text_size = 0;
  62
  63     for (int i = 0; i < size; i++) {
  64         uint8_t code = data[i];
  65
  66         if (code == 0x8f)
  67             break;
  68
  69         char tmp[16] = "";
  70         char *t = tmp;
  71         if (code >= 0x20 && code <= 0x7f)
  72             snprintf(tmp, sizeof(tmp), "%c", code);
  73 #if 0
  74         else if (code == 0x80)
  75             snprintf(tmp, sizeof(tmp), "<i>");
  76         else if (code == 0x81)
  77             snprintf(tmp, sizeof(tmp), "</i>");
  78         else if (code == 0x82)
  79             snprintf(tmp, sizeof(tmp), "<u>");
  80         else if (code == 0x83)
  81             snprintf(tmp, sizeof(tmp), "</u>");
  82 #endif
  83         else if (code == 0x8a)
  84             snprintf(tmp, sizeof(tmp), "\n");
  85         else {
  86             fprintf(stderr, "--> %2.2x\n", code);
  87             t = NULL;
  88         }
  89
  90         if (!t)
  91             continue;
  92         size_t t_size = strlen(t);
  93         text = realloc_or_free(text, t_size + text_size + 1);
  94         if (!text)
  95             continue;
  96         memcpy(&text[text_size], t, t_size);
  97         text_size += t_size;
  98         text[text_size]   = '\0';
  99     }
 100     return text;
 101 }
 102
 103 static subpicture_t *Decode(decoder_t *dec, block_t **block)
 104 {
 105     if (block == NULL || *block == NULL)
 106         return NULL;
 107
 108     subpicture_t *sub = NULL;
 109
 110     block_t *b = *block; *block = NULL;
 111     if (b->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED))
 112         goto exit;
 113     if (b->i_buffer < 128)
 114         goto exit;
 115
 116     int     payload_size = (b->i_buffer / 128) * 112;
 117     uint8_t *payload = malloc(payload_size);
 118     if (!payload)
 119         goto exit;
 120     for (int i = 0; i < b->i_buffer / 128; i++)
 121         memcpy(&payload[112 * i], &b->p_buffer[128 * i + 16], 112);
 122
 123     sub = decoder_NewSubpicture(dec, NULL);
 124     if (!sub) {
 125         free(payload);
 126         goto exit;
 127     }
 128     sub->i_start    = b->i_pts;
 129     sub->i_stop     = b->i_pts + b->i_length;
 130     sub->b_ephemer  = b->i_length == 0;
 131     sub->b_absolute = false;
 132     //sub->i_original_picture_width  = 0;
 133     //sub->i_original_picture_height = 0;
 134
 135     video_format_t fmt;
 136     video_format_Init(&fmt, VLC_CODEC_TEXT);
 137     sub->p_region = subpicture_region_New(&fmt);
 138     video_format_Clean(&fmt);
 139
 140     if (sub->p_region) {
 141         sub->p_region->psz_text = ParseText(payload, payload_size);
 142         sub->p_region->psz_html = NULL;
 143     }
 144
 145     free(payload);
 146
 147 exit:
 148     block_Release(b);
 149     return sub;
 150 }
 151
 152 static int Open(vlc_object_t *object)
 153 {
 154     decoder_t *dec = (decoder_t*)object;
 155
 156     if (dec->fmt_in.i_codec != VLC_CODEC_EBU_STL)
 157         return VLC_EGENERIC;
 158
 159     decoder_sys_t *sys = malloc(sizeof(*sys));
 160
 161     dec->p_sys = sys;
 162     dec->pf_decode_sub = Decode;
 163     dec->fmt_out.i_cat = SPU_ES;
 164     dec->fmt_out.i_codec = 0;
 165     return VLC_SUCCESS;
 166 }
 167
 168 static void Close(vlc_object_t *object)
 169 {
 170     decoder_t *dec = (decoder_t*)object;
 171     decoder_sys_t *sys = dec->p_sys;
 172
 173     free(sys);
 174 }
 175